Hi,
I am having a lot of difficulty with the merge method of NHibernate in .Net 4.

Let's say i have 4 tables, all with the same fields (ID,Version,Name,Associations) : A,B,C,D

A has a list association of Bs.
B has an association to A and To C.
And C an association to D.

Because i transfer my object between tiers, i use DTO objects between layers.

Here is the mapping of class C:


I insert to the database a full graph (all objects and their relations), and from now on i work with corresponding DTO objects.
on the dto object i remove the association to B and create a new association with a new B (full graph).

after converting the DTO back to NHibernate classes, and try to merge these changes, i get an exception:



and this exception vary according to the cascade value in the mappings:




the only way this scenario work as expected (the merge will delete b and will insert the new association with the entire graph) is by marking the cascade option to be s"all-delete-orphan" (but i don't want to delete orphans:))

hope i was clear with my explemation. i will be more than happy to send you further information, this is a main scenarion when working with detached objects and i just cant seem to make this work.

thanks,
Maorino

BTW, when i use SaveOrUpdateCopy, everything seems to work just fine. only 2 issues:
1. this method is marked as deprecated
2. I have implemented code in a CustomSaveOrUpdateEventListener and when using save or update i don't reach this code.

Is there a solution to the issue that merge and SaveOrUpdateCopydoes not attach the objects to the session?

Ok, so i found the solution :)
Apparently i can specify more than one value in the cascade property
for example:


Now the only problem is that the save or update event listener on the save operation on the C class doesn't hit unless i save it first.

Please, any ideas ?